1. Field of the Invention
The present invention relates generally to the field of golf clubs and more specifically, to a set of golf club iron heads in which each such head has a rear cavity and features a redistribution of weight toward the cavity perimeter by employing a thin, lightweight hitting surface which has a plurality of radially extending rear buttresses to resist hitting surface deformation at ball impact.
2. Background Art
Cavity back clubs perform better on off-center hits if: a) weight is removed from the back of the club head creating a cavity; b) weight that is removed is redistributed to the perimeter of the club head; c) the result is a club head that is more stable on impact and deflects less on off-center hits. Off-center hits travel longer and straighter than none cavity back or muscle back designs. Recently larger club heads with larger cavities have proliferated the market. Regardless of manufacture, most iron club head weights are within a few grams of each other (i.e., PING(copyright) No. 5=258 grams, CALLAWAY(copyright) No. 5=258 grams, WILSON(copyright) No. 5=260 grams, etc. (256-262 grams industry standard) therefore the larger the club head designs are limited as to how and where weight can be distributed and still produce the desired performance benefits. A large club head with a larger cavity and thin face would more likely to produce a hitting surface which would deflect/deform at impact thereby reducing energy that would normally be transferred to the ball thus a reduction in performance. A large club head with a large cavity and a thick face would not necessarily deflect or deform, but such a design would tend to have less mass distributed to the perimeter resulting in a less stable club at impact and thus a reduction in performance particularly on off-center hits.
Club heads have been produced with thin face cavities. However, such designs usually produce loud, annoying sounds at impact due to the deflection of the thin face thereof in which acoustic material is attached to dampen the sound.
Depending on the size of the cavity and face thickness of such clubs, some of which use undercuts in the perimeter area to increase effective cavity size, additional acoustic dampening material is attached to or around the back surface of said cavity thereby dampening/quieting the impact sound. It is difficult to produce a club head with a thin face that would not momentarily or permanently deform/deflect at impact and still deliver satisfactory performance. Further it would be difficult to produce a club head with a thin face which would enhance performance on one hand and on the other, sound pleasing at impact.
The present invention comprises an iron head wherein the face thickness is reduced as much as possible and still retains a rigid hitting surface thus allowing the maximum amount of mass in the cavity to be redistributed to the perimeter of said cavity. Such a design results in ball trajectory and dispersion which is more accurate despite off-center hits away from the sweet spot of the golf club face or hitting surface. One way of achieving this is to reduce the face thickness to the point where the hitting surface deflects or deforms upon impact with the ball. The cavity area is modified to accept a lightweight web-like structure which protrudes away from the center of the cavity outward and intersects with the perimeter of the cavity. Thus, the web-like structure has a buttressing effect on the cavity, hitting surface and club head perimeter thus providing a rigid hitting surface. Because the web-like structure separates the cavity into sections, the thickness of the hitting surface can be varied to enhance weight distribution, sound and club head dynamics (i.e., weight placed high and toward the toe will cause the club head to rotate faster than if the same weight were to be placed low and toward the toe).
The present invention overcomes the disadvantages of the prior art by providing a set of golf club irons in which each such iron achieves selective weight distribution. This is accomplished by:
1) Removing weight in the back cavity of the club head and redistributing it to the perimeter of the club head, particularly to the top line, heel, toe and sole.
2) Removing weight in the back cavity to create a very thin hitting surface allowing for additional weight to be redistributed to the club head perimeter. Such a thin hitting surface would flex, deflect or deform either momentarily or permanently upon normal impact with the golf ball.
3) The thin hitting surface is supported by a lightweight web-like structure which acts as a reinforcing buttress preventing flexing, deflecting or deforming; in effect, a rigid hitting surface.
4) A cavity which has a very thin hitting surface supported by a lightweight web-like structure which acts as a reinforcing buttress creating a non-flexing, deflecting or deforming, in effect, a rigid hitting surface. Such lightweight web-like structure separates the cavity into sections such that the face thickness of the hitting surface can be varied to enhance the impact sound and hitting dynamics of the club head.
It is therefore a principal object of the present invention to provide an improved golf club iron head design wherein weight normally in the hitting surface is redistributed to the perimeter of the head rear cavity by thinning the hitting surface and buttressing the rear of the hitting surface with a plurality of radially extending buttress members to prevent or substantially reduce hitting surface deformation at ball impact.
It is another object of the invention to provide a more forgiving golf club iron by employing a lighter weight hitting surface the rear area of which is reinforced by a plurality of web-like sections, the sections being separated from one another by radial buttresses extending toward the perimeter of the rear cavity of the iron head.
It is yet another object of the invention to provide a golf club iron head in which redistribution of weight toward the head perimeter is facilitated by employing either thinner or lower density material hitting surfaces, or both while concurrently preventing or reducing hitting surface ball impact deformation by reinforcing the hitting surface with a plurality of stiffening buttresses.